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Post by cprato on Jul 17, 2012 9:34:26 GMT 9.5
Hi all. I'm new here - long time reader and supporter of BNC though. Keep it up Mr. Brook! I friend posted this article in my FB feed: insideclimatenews.org/news/20120716/fukushima-japan-disaster-nuclear-energy-san-onfore-diablo-canyon-safety-meltdown-peter-lam-expert-interviewI'm curious to hear what the folks around here think. Key quote from the article: "In a presentation before the California Energy Commission in July 2011, Lam raised questions about the NRC's reliance on "likelihood calculations" to guide its safety and plant design regulations. He said the industry practice of not planning for statistically improbable accident scenarios—like the disasters that struck Fukushima—could be catastrophic and needed to end." He may be right about altering risk analysis for reactors, but doesn't elaborate on what he has in mind. What do you all think of this?
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Post by QuarkingMad on Jul 17, 2012 11:01:48 GMT 9.5
If they factor in risk of worst-case-scenario with a very very small probability then rather than introducing it for one specific industry, it must be done for all.
Taking Fukushima for example, how many litres of chemicals spilled into the water when the refinery at Sendai was inundated, then caught fire and released a toxic cloud into the sky?
Singling out one industry or one specific technology that is not primarily designed to kill (i.e. weaponry) for these types of risk scenarios and subsequent application in regulations is an attempt to close or prohibit that technology or industry.
Simpler way would be just prohibiting it, if that is the objective of the person/group proposing it. Look what Australia did, it didn't over-regulate Nuclear power, it just outright prohibited it*.
*I'm not advocating this be done, prohibiting a specific technology based on fear is bad for democracy. Things should fail based on merit, not because we don't like it because it makes people scared.
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Post by anonposter on Jul 17, 2012 12:55:24 GMT 9.5
I think the best attitude to have with regard to events like Fukushima is that if they happen you've got bigger things to worry about than what the reactor does (and that was very much true in Japan). Though I should note that modern passively safe reactors like the AP1000 and ESBWR (not to mention LFTR or IFR) would not have had any problem with the tsunami or power loss (and I understand that US nuclear plants added more redundancy in emergency generation after 9-11). Simpler way would be just prohibiting it, if that is the objective of the person/group proposing it. Look what Australia did, it didn't over-regulate Nuclear power, it just outright prohibited it*. If they could that's exactly what they'll do, over-regulation is used when they can't actually do that (the over-regulation in the US has been an effective moratorium even though it doesn't actually ban it).
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Post by max on Jul 17, 2012 21:05:08 GMT 9.5
What happened to Fukushima Daiichi wasn't a freak accident. Earthquakes and Tsunamis are quite common in Japan, with a frequency measured in decades to centuries. The plant simply wasn't built to withstand a large tital wave, something those who approved its construction should have known better. Geological and historical records point to even larger Tsunamis having occured on this coastline in the past.
Therefore it was not a "statistically improbable accident scenario" - far from it. It had roughly a 1:100 chance of happening each year.
It was going to happen sooner or later, and the Japanese regulators knew that, opting to shut their eyes instead of forcing the operator to construct a higher sea wall an invest in flood proof emergency generators. A 20m sea wall and two generators on elevated ground should have done it ... oh and hydrogen / oxygen recombinators are mandatory equipment in other Western plants ... only in Japan they weren't.
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Post by anonposter on Jul 18, 2012 3:43:33 GMT 9.5
Even so it wasn't just the nuclear plants which weren't properly prepared and there is no reason to single out nuclear for special condemnation when the problem of not being built to handle the local conditions also affected basically everything else there.
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Post by max on Jul 18, 2012 4:21:53 GMT 9.5
It doesn't matter. The point is that this was not an improbable accident scenario. Those responsible for the approval of Fukushima Daiichi failed to take into account what is a very probable accident scenario, which means that the argument "something fundamentally wrong with risk assement for nuclear power plants in general because several reactors suffered a meltdown in Fukushima after being hit by a tidal wave" is not really valid. The reason Fukushima did melt down was because the risk assesment process wasn't carried out properly, or, alternatively, the results of the risk assesment process were simply ignored by operator and regulators. Fukshima has corner cutting written all over it.
Every high schooler can tell you that Japan sits on the ring of fire and experiences strong earthquakes and tidal waves frequently. The sea wall was ridiculously undersized based on historical tsunamis in the same area.
I maintain that there is nothing wrong with the risk assesment process, as long as it is carried out properly and its results are not ignored. Proper site assesment before construction should have figured out the height of past tidal waves. MODERATOR Your post has been edited to remove a snide remark against a commenter. BNC does not allow this type of personal attack.
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Post by anonposter on Jul 18, 2012 5:10:11 GMT 9.5
From what I heard they designed it based on what they knew to be the maximum ground shaking and wave height for that location but then a bit later on some new evidence of a past tsunami (similar in size to the one which hit the plant) appeared.
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Post by sod on Jul 18, 2012 6:52:16 GMT 9.5
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Post by proteos on Jul 18, 2012 7:47:12 GMT 9.5
What do you all think of this? I think it is going to be the last line of defense. It will not be particularly developped, it will be mainly a fast reaction force that is ready to bring emergency means on site by air rapidely. Note that it is less expensive to maintain such a force if you have a relatively high number of nuclear plants on a relatively small territory, because of the pooling effect. This is not completely unnecessary. It is notorious that TEPCO did not listen to advance warnings that a tsunami may be higher than initially forecast, didnot install venting filters, etc. As there may be some reluctance to incorporate new data, take action on this data & that some unexpected event might happen, such a force may make the difference between a large evacuation and a news item one day on page one. But as usual all rests on a cost-benefit analysis.
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Post by proteos on Jul 18, 2012 8:04:57 GMT 9.5
Let us be clear about this: the figure seems to come from an application of the linear no threshold model. UNSCEAR in its 2010report states that for an acute exposure of 100mSv, one can expect ~0.5% excess deaths from cancer, with a quite large error margin of 0.2%. Below this no one has ever been able to discern an effect from the background noise inherent to all epidemiological studies. But in radioprotection it makes sense to use a linear model below this 100mSv dose because it allows to make choices of radio protection investments based on a value of life and the expected value of excess deaths. But make no mistake: it also means that no one will ever be able to discern 130 excess deaths against the deaths from cancer occurring from other causes in Japan. That's probably why UNSCEAR states in its 2008 assessment about Chernobyl that (§D252 p183)
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Post by QuarkingMad on Jul 18, 2012 10:16:51 GMT 9.5
To add onto proteos's comments. The figure is not not definite. It is probably 15 to 1,300 most likely at 130. That is a large margin of error. It's like someone saying the temperature tomorrow will be between 10 and 30 degrees Celsius with most likely temp at 13. Not very accurate. This is a regulatory and cultural created crisis. At the end of the day the technology will only be as safe as those who regulate and take on advice of modelling.
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Post by David B. Benson on Jul 19, 2012 15:20:20 GMT 9.5
max --- With but a single exception none of the world's seismologists thought the Tohoku fault was capable of generating more than a moment magnitude 8.0 earthquake, maybe just possibly an moment magnitude 8.3 earthquake. So nobody expected such a large tsunami.
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Post by max on Jul 20, 2012 14:36:23 GMT 9.5
Tsunami height is not only a function of quake magnitude but also depends on the movement of the sea floor and local topography. Sometimes a high magnitude earthquake doesn't generate a tsunami at all.
The point is that before or a while after plant construction commenced (don't remember when exactly) evidence had been uncovered of a past tsunami far higher than the plant's sea wall, yet the regulators did nothing.
The Fukushima accident confirms the importance of a truly independent regulator. In Japan's "nuclear village" everyone was in bed with everyone, and subsequently corners were cut to enhance profit. That's the story of Fukushima, it has nothing to do with alleged inherent flaws in probablistic risk assesment.
carnegieendowment.org/2012/03/06/why-fukushima-was-preventable
In short, risks weren't rationally and thoroughly analyzed for a variety of non-technical reasons. Best practice was ingored in Japan, threats to plant safety were played down our outright ingored.
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Post by max on Jul 20, 2012 15:15:53 GMT 9.5
Part of the report directly relating to risk assesment:
"In numerous countries outside Japan, plant-specific probabilistic safety assessments routinely estimate the contribution of both internal and external events to core damage frequency—a common yardstick for nuclear power plant safety. In some of these countries, regulators required owners to design their installations to withstand a thousand-year flood event, and probabilistic methods were used to calculate the height of that flood. After the Blayais event in France, some countries imposed the requirement that nuclear power plants withstand a ten-thousand-year flood. European regulations for some events require that a one-million-year event is considered. IAEA guidelines encourage including both external and internal events in plant-specific probabilistic safety assessments."
"According to Japanese government and industry officials, most Japanese safety rules follow from deterministic assessments. Regulations do not require probabilistic safety assessments to demonstrate that plants are protected against the threat of severe external events. Japanese experts said that especially after a severe earthquake damaged the Kashiwazaki-Kariwa Nuclear Power Station in 2007, plant-specific seismic probabilistic safety assessments in Japan have been carried out on an experimental basis but as of the date of the Fukushima accident, the results had not been used by owners or regulators in decisions about making design modifications."
Emphasis mine.
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Post by sod on Jul 22, 2012 17:22:23 GMT 9.5
To understand the situation in japan, we have to carefully follow the japanese news. (hint: add ....location:japan... to relevant searches in google) We now know, that workers at the fukushima plant were forced to cover their dosimeters with lead, to prevent it from constantly giving alarm sounds. www.japantimes.co.jp/text/nn20120722a1.html#.UAuvWqNCmkQThis incident alone should strip Tepco of the right, to ever run a nuclear power plant again. Tepco is responsible for its subcontractors and has to establish control mechanisms and ethic standards that keep anything like this from happening.
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Post by shinjukusam on Jul 23, 2012 1:26:54 GMT 9.5
To understand the situation in japan, we have to carefully follow the japanese news. (hint: add ....location:japan... to relevant searches in google) We now know, that workers at the fukushima plant were forced to cover their dosimeters with lead, to prevent it from constantly giving alarm sounds. www.japantimes.co.jp/text/nn20120722a1.html#.UAuvWqNCmkQThis incident alone should strip Tepco of the right, to ever run a nuclear power plant again. Tepco is responsible for its subcontractors and has to establish control mechanisms and ethic standards that keep anything like this from happening. What do you propose the site manager do, walk around with a metal detector?
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Post by QuarkingMad on Jul 23, 2012 9:50:12 GMT 9.5
To understand the situation in japan, we have to carefully follow the japanese news. (hint: add ....location:japan... to relevant searches in google) We now know, that workers at the fukushima plant were forced to cover their dosimeters with lead, to prevent it from constantly giving alarm sounds. www.japantimes.co.jp/text/nn20120722a1.html#.UAuvWqNCmkQThis incident alone should strip Tepco of the right, to ever run a nuclear power plant again. Tepco is responsible for its subcontractors and has to establish control mechanisms and ethic standards that keep anything like this from happening. I thought it was a contractor that told their employees that worked on site cover their dosimeters so they could work there longer. Rather than being a direct TEPCO employee. Confirmed in the first paragraph of the article linked: Sounds like a sub-contractor didn't want to give up a contract too early, rather than the evil TEPCO narrative doing the rounds. If something wants to be blamed, blame the Japanese business culture that the report into the disaster highlighted as the root cause. Considering the limits of the original search option the OP posted this may not be enough as which new organisation would publish articles blaming their own business culture en masse? Good to get info from inside, but an outsiders option is just as good. It's why we pass on assignments and papers to peers to check to see if we missed something.
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Post by sod on Jul 23, 2012 15:46:24 GMT 9.5
Tepco is responsible for its subcontractors. Actually i think subcontractors should be limited to the absolutely necessary minimum in an industry like nuclear power.
And yes, Tepco has to check occasionally, if contractors stick to the rules. They also have to estimate what the dosimeter shows and compare this to what it really shows, to check if everything was done correctly.
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Post by singletonengineer on Jul 28, 2012 23:31:03 GMT 9.5
The Stanford article about 130 probable deaths from Fukishima was reported widely, including by Australia's ABC, as 1300. This factor-of-ten error is only part of the problem. The Stanford article's author has been criticised as having an antinuclear stance. Let's wait for peer review which looks into the methodology behind the predictions before we get too excited. These predictions spread across almost a 100-fold range, so the actual figure is, clearly, highly imprecise and questionable. However, headlines such as "Dr Caldicott's estimate of death toll is 1.9 million percent above the average of an expert's estimate" do not sell newspapers. Here is a partial quote from Stanford's press release: " the researchers found a range of possible death tolls, from 15 to 1,300, with a best estimate of 130". Here is the actual press release: news.stanford.edu/news/2012/july/fukushima-health-impacts-071712.htmlHere is a note about Caldicott's predictions, as it appears in the third comment on the above article: " MarkGoldes at 11:39 AM July 17, 2012: Helen Caldicott MD has stated that the total deaths from Fukushima Daiichi might eventually reach 2.5 to 3 million." I wonder which figure is remembered by the undiscerning reader: The Stanford lower limit of 15, which is still likely to be questioned, or the Caldicott millions? Is an intemperate shout louder than a considered whisper?
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Post by David Walters on Jul 31, 2012 2:36:00 GMT 9.5
A few comments. If I have to "choose" Jacobson over Caldicott I'll choose the former despite his own inane comments and views on the subject. It is interesting that I had to learn of Caldicotts lies here, on BNC, and not in the press.
Of Seawalls and Prophylactics...
It is not true as some had stated that "If it were a AP1000 (or IFR or LFTR) that this would not be a problem". It would be problem had the same thing occurred. What passive cooling does is to reduce the risk by huge orders of magnitude. It is not fool proof (nor does it have to be).
Protection and treating outside external natural threats prophylacticly isn't as simple as one can make it out to be. The issue of the sea wall is one such simplistic POV expressed here, and by myself until I learned more about it. The problem is not with the height, per se, but with the design. Even a 14m sea wall (height of the now destroyed seawall at Fukushima) built out to a height of 20m (60 ft) would of done *squat* to stop this tsunami!
The seawall design used was the cheapest 'gravity' supported seawall type, made up of individual 'caltrop' steel/concrete pieces that were laid, or dumped, on top of one another with cable bindings and fittings. This is the weakest kind of sea wall. It's actually designed to allow water to flow through it. It is really designed to temper, not stop, a large wave. A 20m seawall of this type would of been swept away as well, possibly, even likely.
A better approach could of been used. A large true seawall of the Dutch dam design, using large rocks (5 to 30 ton in weight) build with a very wide base, 200 meters if need be, and build to about 15m would stop a wave 20m or more in height. People are over focused on stopping the tip of wave than with the force behind that wave.
Secondly, structurally *built* wall would mean a larger expense. You could use caison style dam-like construction with struts sunk into the sea flaw and used poured concrete.
TEPCO was following standard Japanese sea wall construction of the *cheapest* and least effective type. This is always TEPCO's problem...they build only to the regulatory requirement (which they and a few other utilities have always controlled).
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Post by sod on Aug 2, 2012 16:34:12 GMT 9.5
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Post by proteos on Aug 3, 2012 7:04:43 GMT 9.5
Taxpayers now pay 1 trillion yen ($12.78 billion) to save Tepco. Shareholders are nearly completely protected from any loss. And the state of Japan, which now basically owns Tepco, might compromise changes to security to protect its investment. ajw.asahi.com/article/0311disaster/fukushima/AJ201207310068This is contradictory. TEPCO has been making huge losses and its prospects are not very good, to put it mildly. The share price must have dropped steeply, and it duly has. Because TEPCO has cut corners in the past, the last shareholders have lost most of their investment.
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Post by quokka on Aug 3, 2012 10:07:25 GMT 9.5
The Bloomberg chart only shows a max of one year price history for TEPCO. Go back before the accident and it is apparent that almost all shareholder value has been wiped out: www.marketwatch.com/investing/stock/9501?countrycode=jpFrom well over 2,000 yen per share to yesterday's close of 149. I really don't know why people continue to make nonsense claims about this, when it is so easy to check the facts.
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Post by sod on Aug 4, 2012 16:05:16 GMT 9.5
If you look at the 5 year graph, you see that Tepco fell from nearly 3500 to 2000 yen over the 4 years before the accident. (nearly a cut in half) www.marketwatch.com/investing/stock/9501?countrycode=jpin then took a dramatic hit by the Fukushima accident. So what the article i linked above and I complain about, is something different. losing money with stocks, is pretty normal. But Tepco is bankrupt and the investors should not still own nearly 10% of their investment and the possibility of getting even more money back. There are legitimate reasons for saving Tepco with tax payer money. (for example keeping the jobs and the hope that a part of the company might recover. But there are serious problems associated to this as well. The Tepco employees who have failed their responsibilities in preventing the accident keep their jobs. We also avoid serious discussions about the problems associated to the bankruptcy of a nuclear company.
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Post by quokka on Aug 4, 2012 18:31:18 GMT 9.5
As far as I am aware Tepco is not bankrupt. Bankruptcy is a specific legal status usually imposed by court order when creditors lose confidence in the capacity of an individual or organization to meet financial obligations.
Large sums have been in injected into Tepco via bank loans and by the government of Japan taking a controlling interest. The mechanism of the latter is presumably Tepco issuing a large number of new shares and selling them to the government. Of course this dilutes existing shareholder value, but that is already priced in by the market.
Will Tepco be able to trade it's way out of difficulties, repay the loans and provide some sort of return to the government on it's equity stake as well as pay compensation? Who knows.
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Post by sod on Aug 6, 2012 6:02:38 GMT 9.5
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Post by sod on Aug 7, 2012 5:19:21 GMT 9.5
Asahi Shimbun has a follow-up piece, showing that hiding dosimeters is a common practice, while working in japanese nuclear power plants. ajw.asahi.com/article/0311disaster/fukushima/AJ201208060093This is a pretty sad story and we can only hope that those who looked away will be punished for allowing this to happen!
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Post by QuarkingMad on Aug 7, 2012 9:27:24 GMT 9.5
TEPCO is a company that owns more than just the reactors at Fukushima though. They have a wide portfolio of energy assets that require maintainence, fuel etc. to provide power. Such as their gas and oil plants that are filling the gap created by the Nuclear shut-down country wide. The "bailout" is to ensure the energy security of TEPCO's other assets that are currently providing the Japanese with electricity.
Does the Japanese government allow these to be shut off to? Or inject money to keep the company viable so they can cope with the impact of the Fukushima costs while being able to secure the rest of their energy assets? That is the question that needs to be asked.
This feeds back into the risk calculations the OP's link noted.
It's already been noted that business and general culture in Japan was a major contribution to the crisis heading down the path it has. What more do you want sod? Japanese government to buy TEPCO and take on the liability, dismantle TEPCO and feed it to the other energy companies, or something else?
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Post by sod on Aug 10, 2012 16:51:01 GMT 9.5
I think that the state of Japan should have let Tepco go bankrupt.
This would not have prevented them from taking over the running power plants, though it might have caused a little more disturbance.
But it would have exposed many weaknesses of the nuclear industry (like who is responsible for the Fukushima clean up?) and made it eassier to punish those responsible at Tepco.
I do not know, whether people here are following the release of Fukushima videos. even the tiny parts we have now, show an incredible amount of deception and the will to risk lifes to save the reactors. (seawater injection) (Deleted violation of the Comments Policy) i think that this kind of behaviour undermines confidence of people in nuclear power. So i really think that even supporters of nuclear should be interested in getting the truth out and punishing those, who did not even follow their own rules! MODERATOR You continually violate the comments policy as stated below:
Citing literature and other sources — appropriate and interesting citations and links within comments are welcomed, but please DO NOT cite material that you have not yourself read, digested and understood. As a general rule, please introduce any and every link or reference with a short description of the material, your judgement on its quality, and the specific reason you are including it (i.e. how it is relevant to the discussion).
Former instances have been allowed, but as this now seems to happen with almost every one of your comments the rule will be applied in future.
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Post by sod on Aug 10, 2012 17:40:04 GMT 9.5
The following link contains information about the process of injecting sea water into the Fukushima reactor. It also shows that Tepco was reluctant to inject seawater, as they feared that it would damage the reactor. www.japantimes.co.jp/text/nn20120810a3.htmlAs the material comes from a video showing the Tepco discussions during the accident, the material is of very high value. The original article of this post was about the challenges to nuclear safety analysis after Fukushima and how the accident changed the opinion of an expert. Now with the videos, we finally have a first real evidence of the internal handling of the accident. It shows exactly the same risk assessment structure as was demonstrated by not having the 2 additional back up diesels at higher elevations (an example given by the expert in the original article) It is also very relevant to the panel discussed in the original article. such a security panel should also look at how decisions are made and which factors (reactor damage of risk of meltdown) are considered to be more important.
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